Evaluation of real-time communication performance in QoS-enabled infrastructure WLANs

Nowadays, industrial communication systems are experiencing the introduction of wireless technologies at all levels of automated factories. The benefits that derive from such a choice are manifold, including reduced deployment costs, enhanced flexibility and support for mobility. Unfortunately, because of a number of reasons, wireless systems can not be thought of as a complete replacement of wired networks at the field level. In this paper, the performance that can be achieved by QoS-enabled WLANs to support communication in industrial environments is analyzed. In particular, a detailed analysis of latencies in infrastructure networks is presented, obtained through numerical simulations, that takes into account both media access and queuing delays. Moreover, the impact of the internal architecture of the access point on performance is evaluated as well.